1. Field of the Invention
This invention relates to a device that uses a fluid to dampen a force which tends to move the plane of rotation of a steerable wheel or wheels of a vehicle having a shaft used to steer such wheel or wheels away from being generally parallel to the frame of such vehicle. It also relates to such a device for any steering mechanism, such as a ski of a snowmobile or the exhaust jet of a personal watercraft, that uses a shaft or the like and a handlebar or the like in the steering process. For convenience, the term “motorcycle” will be used herein; this term includes, though, not only a traditional motorcycle but also any vehicle using a steering mechanism as discussed in the preceding sentence.
2. Description of the Related Art
Dampening devices of the type subject to the present invention are those which contain a rotatable wiper in a housing having a channel (or circuit) running from a portion of the housing on or near a first side of the wiper to a portion of the housing on or near a second side of the wiper so that when the housing is filled with fluid, as the wiper is moved, it forces fluid through the channel (or circuit). Such devices are herein termed either dampeners or stabilizers with the two terms being considered synonymous with one another.
Examples of such devices are those of U.S. Pat. Nos. 4,773,514; 6,401,884; U.S. patent application Ser. Nos. 10/166,498; and 10/801,626.
Generally, some form of valve is placed within the channel (or circuit) in order to control the degree of dampening. This is usually accomplished by varying the effective cross-sectional area of the channel (or circuit).
U.S. Pat. No. 6,802,519, the application for which was filed on Sep. 9, 2002, utilizes at least two channels (or circuits) to control the degree of dampening. The first such channel (or circuit) employs the type of valve first described and claimed in U.S. patent application Ser. No. 10/166,498. In lines 39 through 41 of column 3, U.S. Pat. No. 6,802,519 explains, “The adjustment is ‘progressive’ in that no flow stoppage occurs between different positions of the valve.” This valve 27 is shown in FIG. 5 to have a shaft with a continuous indentation cut around the shaft in such a manner that for a first area there is no cut in the shaft and then the indentation commences and becomes increasingly deeper as it progresses around the shaft until the continuous indentation stops upon reaching the first area.
The second channel and the second valve 28 are never disclosed or claimed to exist without the first channel and its valve 27. Lines 21 through 24 in column 3 of U.S. Pat. No. 6,802,519 explain, “Manual adjustment of resistance to fluid flow through a second circuit is effected by a manually manipulated progressive valve 28 positioned near a hand grip 16 on the handlebar 15.”
Lines 25 through 29 of column 3 further provide, “Communication with the two sides of chamber 19 is provided by a pair of ports 29 and 31 drilled in the lower face of cover member 22 . . . These ports allow for flow of hydraulic fluid in and out of chamber 19 through each of the hydraulic circuits provided in the damper.”
And lines 42 through 51 of column 3 complete the description of the second channel (or circuit) and valve 28: “A second hydraulic circuit communicating with ports 29 and 31 is provided by hoses 34 communicating with cover member 22 and progressive valve 28. The construction of valve 28 is illustrated in FIGS. 7 and 8 and comprises a thumb or finger handle 35 for turning a stem 36 having a bore 37 therethrough for selectively adjusting the resistance to fluid flow through a passage 38 in the body of valve 28 which connects the hoses 34. The stem 36 of valve 28 can be turned from closed to full open of passage 38 to reduce resistance to fluid flow and reduce dampening.”
Three factors appear to the present inventor to dictate that the second circuit and the second valve 28 in the Steering Damper of U.S. Pat. No. 6,802,519 are neither disclosed nor claimed to exist apart from the first circuit and the first valve 27.
The first, and one of the two more significant factors, is that when a valve remote from the housing of the dampener is utilized to control degree of dampening, it is crucial to select a range for the internal diameter for every portion of the circuit (As utilized herein, the term “circuit” designates each and every aperture, port, channel, passage, tube, line, hose, or the like that is used in order to connect a valve to the interior chamber of the housing for a dampener and, thus, to permit fluid communication between such interior chamber and such valve.) in which the fluid flows (other than the control valve, itself) that will permit the fluid to flow freely at high speed but that will also create the fluid pressure necessary for effective dampening; but within U.S. Pat. No. 6,802,519 there is no discussion of such internal diameters.
The second factor, which is closely related to the first, is that the circuit between the housing of the dampener and the remote valve must be constructed so that it maintains its internal diameter within the crucial range discussed in the preceding paragraph, but U.S. Pat. No. 6,802,519 does not deal with this matter.
Third, the quoted description of the remote valve 28 above is a construction creating great difficulty in selecting and maintaining a desired setting other than on or off.
U.S. patent application Ser. No. 10/166,498, filed on Jun. 10, 2002, discloses a valve to be inserted into a channel (or circuit) of a dampener for controlling the degree of dampening wherein a continuous indentation is cut around a shaft in such a manner that for a first area there is no cut in the shaft and then the indentation commences and becomes increasingly deeper as it progresses around the shaft until the continuous indentation stops upon reaching the first area.
And U.S. patent application Ser. No. 10/801,626 includes a dampener which is designed for installation below the handlebars of a motorcycle, although it does not have a wiper in the housing with such wiper having a depression in its bottom to accommodate the stem nut which holds the top of the steering shaft that permits the motorcycle wheel to move left and right.